- Premenopausal patients must agree to use adequate contraception for the duration of protocol treatment and for 6 months after the last treatment with palbociclib. Adequate contraception is defined as one highly effective form (i.e. abstinence, male or female sterilization) OR two effective forms (e.g. non-hormonal IUD and condom/occlusive cap with spermicidal foam / gel / film / cream/ suppository). Hormonal contraceptive methods are not allowed.